Drew Barrymore’s half-sister Jessica was found dead in her car on Tuesday.

Jessica Barrymore, who shared the same father as Drew, was found in a vehicle in National City, just north of San Diego, California at 6am.

According to reports, local resident Marta Lopez found Jessica, 47, slumped behind the wheel of the car, which had blocked the driveway to Lopez's apartment building. Pills were discovered on the passenger seat and a can of energy drink was wedged between her legs.

The Medical Examiner's Office confirmed her identity to local radio station 10News.

An autopsy will be carried out to determine the cause of death.

Jessica would have turned 48 on Thursday. She is the daughter of John Drew Barrymore and his third wife Nina Wayne.